<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <div>
      <img src="./imgs/1t.png" />
    </div>
    <script>
      var num = 1;
      var imgEle = document.querySelector("img");
      // 单纯的从第一张切换到第五张图；
      setInterval(function () {
        num++;
        console.log(num);
        imgEle.style.transition = "all 1s";
        imgEle.style.opacity = 0;
        imgEle.ontransitionend = function () {
          imgEle.src = `./imgs/${num}t.png`;
          imgEle.style.opacity = 1;
        };
        if (num == 5) {
          num = 1;
        }
      }, 2000);
    </script>
  </body>
</html>
